<!DOCTYPE html>
<html>

<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <link rel="stylesheet" href="../bootstrap-5.1.3-dist/css/bootstrap.css">
  <script src="../bootstrap-5.1.3-dist/js/bootstrap.js"></script>
</head>

<body>

  <body>
    <div class="container p-5 my-5 border">
      <h1>容器样式A</h1>
      <h3>有边框和额外的内边距和外边距。</h3>
    </div>
    <div class="container p-5 my-5 bg-primary text-white">
      <h1>容器样式B</h1>
      <h3>有蓝色背景色和白色文本，以及一些额外的边距。</h3>
    </div>
    <div class="container p-5 my-5 bg-dark text-white">
      <h1>容器样式C</h1>
      <h3>有深黑色背景色和白色文本，以及额外的内边距和外边距。</h3>
    </div>
  </body>

</html>